Radio receiving set



Patented Dec. 8, 1931 UNITED STATES PATENT OFFICE RADIO RECEIVING SETApplication led August 8, 1929. Serial No. 884,327.

This invention relates to radio receiving apparatus, having for itsobject the provision of certain desired improvements in the way of amore efficient method and construction for arranging and shielding thevarious units forming the modern radio receiving set Y chassis.

Another object is to provide a shielded radio receiving set chassis of atype particularly adapted for quantity' production while affording themaximum in the way of an electrically eilicient disposition of thetuning means employed, and a protection against dust, moisture andtampering.

Other objects and advantages of the method and construction employedwill appear more 'fully in the details hereinafter set forth when takenin connection with the accompanying drawings in which:

Fig. 1 is a perspective view, with parts broken away, of a radioreceiving set embodying my invention;

Fig. 2 is an enlarged plan sectional view, taken on the line 2 2 of Fig.4;

Fig. 3 is a plan sectional view, taken on the line 3 3 of Fig. 4;

Fig. 4 is a transverse sectional view taken on line 4-4 of Fig. 2; and

Fig. 5 is a fragmentary enlarged detail 30 view showing the manner inwhich some of the shielding means are applied to the chassis.

In the drawings wherein similar characters of reference indicatecorresponding parts in the several views of the preferred form of myinvention, A designates the receiving set chassis as a whole whichincludes the panel 9 to which is secured an elongated comparativelyshallow metal casing 10, the latter providing a shielding housing forthe wiring hereinafter described more fully. As best shown in Figures 2and 4, the casing 1() comprises an upper section 11 of substantiallyrectilinear shape, and having a downwardly projected flange 12, whichlatter is secured 45 by bolts 13 to the upwardly projected flange 14 ofthe bottom section 15 of the container 10. The bottom section 15 isfurther provided with longitudinally extending upwardly proj ecting ribsor partitions 16, which latter provide the compartments 17, 18 and 19.In the compartment 17 the alternating current Wires 20, 21, having theleads 22, 23, are housed. In the compartment 19, the plate, grid andcathode wires 24, 25 and 26respectively, are installed, having thecorresponding short leads 24, 25 and 26. In the central compartment 18all the short leads from the alternating current wires and the gridplate and cathode energizing wires together with the short leads 27 arebrought, it being observed 60 that all the vacuum tubes which includethe screen grid tubes 28, and the conventional alternating currentheater type tubes 28l are mounted in a manner permitting the vacuum tubeprongs (not shown) to be directly joined to the above mentioned leads.

Secured to or integral with the bottom of the lower section 15 of thecasing l2 is a downwardly depending wall 29 which extends the entirelength of the casing 10. On one side of the partition 29, as best shownin Figure 4, a series of shielding containers 30 are secured, it beingobserved that a bayonet slot 31 is provided in one of the walls of eachof the containers 30, these slots serving to accommodate the heads ofsmall bolts or rivets 32 secured to the partition 29. In assembling thechassis A, it will only be necessary to pass the heads of the metalbolts 32 into the bayonet slots 31, in order to secure the metalcontainers 30 in position to shield the transformers 33, which lattertogether with the condensers 34 mounted on the opposite side of thepartition 29 form the other part. As clearly shown in Figures 3 and 4,it will be seen that the condensers 34 in the present instance comprisefour separate units, which may be operatively joined in any suitablemanner as by the chain or band 35, appropriately connected to the shafts36 of the rotors of the condensers 34. A manipulating knob 37 secured ona shalt 38 directly connected to one of the rotor shafts 36 serves as ameans to operate all of the tuning condensers 34 simultaneously.

The present radio receiving apparatus is designed for alternatingcurrent energization, it being essential that the wiring of radio setsof this type be shielded to prevent electromagnetic inductive etlects inthe wires 24,

25 and 26 connected'to the plate, grid and cathode wires of the vacuumtubes employed. In Figure 2 it will be particularly noted that thealternating current wires 20 and 21 are closely twisted together andthen placed in a separate compartment 17. The other wires 24;, 25, 26are housed in the compartment 19 of the container 12 while the shortleads 27 from the screen grid tubes 28, as pointed out above, arecarried directly into the middle compartment 18. Practically all thetuning instrumentalities that require shielding are thus separated andshielded in separatelcompartments, it being particularly desirable, asis well known, to shield the various electrical units employed,particularly the radio frequency coils or transformers 33 and thealternating current feed wires. In receiving sets of the alternatingcurrent type herein illustrated, thenegl'ect to shield one unit alonemay result in causing an electro-magnetic intercoupling, which is liableto introduce a considerable degree of distortion in reproduction.

The'present radioV receiving chassis is particularly designed andadapted for quantity production on av large scale, it being observedthat the casing 10, the containers 30, the panel 9, and the partition 29are preferably stainpings, which'may beconveniently and quicklyassembled to formv the completed unit shown in Figure 1, the chassisthere shown being ready for immediate installation into a-suitablecabinet. The entire chassis which is preferably of all metal may `begrounded, which' will stilly further reduce any tendency towards bodycapacity and undesired electro-magnetic intercoupling.

"While I haveY described and illustratedv a preferred form of myinvention, itV will be* understood that thel construction anddisposit'ion` of parts maybe modified and changed' receiving set, acomparatively shallow casing' removablysecured to said panel, aplurality off compartments in said casing, one of saidcompartments-separately receiving the alternat-ing current energizingwires of said radio receiving set', another of said 'compartmentsreceiving other wires leading to the electrodes ofV vacuumV tubesVremovably and operatively secured in an upper section of said casing,

andv a 'downwardly Vproj ecting partition secured toanotlier section ofsaid casing, said partition providing a meansfor supporting aplurality'of transformers on one side thereof,

and a plurality of condensers on the other side thereof, saidtransformers being individually segregated and shielded by containersremovably secured to said partition.

2. A radio receiving setV chassis comprising Va casing, said casingincluding an upper section, a lower section receivable in said uppersection, said lower section having a plurality of flanges, said flangesserving-to separate the container formed by the conjunction of saidupper and lower sectionsinto a plurality of compartments, one of saidcompart- .ments receiving the alternating current enerper section, saidlower section having a plurality of flanges, said flanges serving toseparate the container formed bythe conjunction of said upper and lowersections into a plurality of compartments, one ofisaid compartmentsreceiving the alternating current energiziiig` wires of theV saidchassis, another kof said 'compartments receiving the plate, grid andcathode energizing wires of the chassis, a third compartment receivingthe prongs of vacuum tubes and the short lead wires from the saidalternating currentplate, grid and' cathode energizing'wires, and apluralityof shielding compartments, each arranged to contain atransformer.

45A radio .receiving set chassis comprising acasing, said casingincludingan upper section, a'lower section receivable in said uppersection, said lowersection having a plurality of Hanges, said flangesserving to separate the container formed by the conjunction of saidupper and Vlower sections into aA plurality of compartments, one of saidcompartments rec'eiving'the alternating Vcurrent energizingw-ires of thesaid chassis, another of said compartments receiving the plate, grid andcathode energizing wiresofthe chassis,

a third compartment receiving the prongs of vacuum tubes and theshortlead wires from the said' alternatingA current plate, grid andcathodeenergizing wires, a pluralityfof shielding compartments, eacharranged to contain a transformer, and a plurality of condensers mountedwithout said wire and transformer containing compartments.

In testimony whereof I have -signedmy name to this specification. l

FREDERICK A. GEHM.

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